This is a phase-II study of 141W94/VX-478 plus 3TC plus ZDV or indinavir plus nevirapine plus 3TC plus stavudine in subjects previously treated with 141W94/VX-478. Approximately 94 subjects will be studied. The study population will consist of subjects who have successfully been treated with a regimen that includes 141W94/VX-478, OR subjects who have failed or are intolerant to a treatment regimen that includes 141W94/VX-478. Subjects enrolled to ACTG 347 who prematurely discontinued study medications and were treated with open-label IDV + NVP + 3TC + d4T will also be eligible to participate. Subjects will receive one of two treatment regimens: Arm A (subjects with < 500 copies HIV-1 RNA/mL on a regimen containing 141W94/VX-478) will receive 141W94/VX-478 (1200 mg q 12 hr) plus ZDV (300 mg q 12 hr) or d4T (40 mg q 12 hr) plus 3TC (150 mg q 12 hr). Arm B (subjects with 3 500 copies HIV-1 RNA/mL or intolerance to a regimen containing 141W94/VX-478) will receive IDV (1000 mg q 8 hr) plus NVP (200 mg bid) plus 3TC (150 mg bid) plus d4T (40 mg bid).